What is so interesting about the development of the 'Mass' is, for 300 years, the Church's only 'oblation' was the offertory—which Protestants still offer today—but suddenly at the end of the 4th century, it becomes a propitiatory offering of Christ's body & blood. A novelty.

I agree: Jesus celebrated the Last Supper, but His only 'sacrifice' there was gratitude in accordance with Psalms 50:14, 'Offer to God a sacrifice of thanksgiving.' I agree that the Didache makes reference to the Eucharist, as does Justin. Neither offered Jesus' body & blood.

Brian's infallible authority—Popes Pius IX, X, XII & Leo XIII all took Gen 3:15 as 'unmistakable evidence that she crushed the serpent's head.' Only for JPII to admit that it's not: 'Exegetes now agree [it] does not attribute action against the serpent directly to the woman.'